Hooker-Raschig process

Vapor phase hydrolysis of chlorotoluenes appears to be accompanied by a much smaller degree of isomerization than liquid phase hydrolysis, and accordingly, the Hooker-Raschig process is considered more attractive than the original Dow process. The process, however, is much less attractive than the sulfonation and alkylation processes. The chemistry of the process is as follows ... 

These processes perform the oxidation of hydrochloric add in situ. Their principle is similar to the one implemented to produce phenol from benzene by the Hooker/Raschig process (see Section 10.1.3). The first industrial ethylene oxychlorination plant was built by Dow in the United States in 1955. 

In the 1930s, the Raschig Co. in Germany developed a different chlorobenzene-phenol process in which steam with a calcium phosphate catalyst was used to hydrolyze chlorobenzene to produce phenol (qv) and HCl (6). The recovered HCl reacts with air and benzene over a copper catalyst (Deacon Catalyst) to produce chlorobenzene and water (7,8). In the United States, a similar process was developed by the BakeHte Division of Union Carbide Corp., which operated for many years. The Durez Co. Hcensed the Raschig process and built a plant in the United States which was later taken over by the Hooker Chemical Corp. who made significant process improvements. 

Chlorination of benzene and catalytic saponification by Cu in the steam hydrolysis of the chlorobenzene (Raschig process, Raschig-Hooker, Gulf oxychlorination). 

The latter two methods are variants of the Hooker/Raschig and Dow processes, which are already industrialized. 

The procedure described above is a variant of the Raschig process and was developed by the Hooker Chemical Co. (U.K.) in 1964. The improvements over the original Raschig process (about 1930) include the hydrolysis catalyst, which renders unnecessary the separation of dichlorobenzenes, and the single distillation train. The Hooker process gives an overall phenol yield of 85—90% and has practically no requirement of auxiliary chemicals. 

The reaction takes place at 430 C in the presence of a silicon catalyst. The process is named after German chemist Fritz Raschig (1863 1928). The Hooker-Raschlg process is a variation and uses a different type of catalyst. 2. A two-step process used for the production of hydrazine using the oxidation of ammonia with sodium hypochlorite in the presence of gelatine ... 

Benzene Oxychlorin tion. In the benzene oxychlorination process, also known as the Raschig Hooker process, benzene is oxychlorinated with hydrogen chloride, air, and with the presence of iron and copper chloride catalyst to form chlorobenzene. The reaction occurs at 200—260°C and atmospheric pressure. The chlorobenzene is hydrolyzed at 480°C in the presence of a suitable catalyst to produce phenol and chloride. The yield of phenol is - 90 mol% of theoretical. These plants have been shut down for environmental and economic reasons. 

Raschig (2) Also called Raschig-Hooker. A two-stage regenerative process for making phenol from benzene. The benzene is first chlorinated with hydrochloric acid in the presence of air, at 200 to 260°C, over a copper catalyst on an alumina base ... 

This process is covered by a number of patents, in particular U.S. 1,963,761 and 2,035,917, which are assigned to F. Raschig, G.m.b.H. In the United States, the process was developed by Durez Plastics and Chemicals Corporation (now a division of Hooker Chemical Company) and is now used by other firms. See also B.I.OJS. Final Re-pls. 507 and 1841, Item No. 22. 

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